The invention relates to a connecting device for the power supply to equipment in heating devices, particularly auxiliary heating devices in vehicles. Generally, the following are involved: a combustion motor, a control unit for the heating device, a circulating pump, a solenoid valve, an ignition spark unit, a flame monitoring device, and in certain cases, a preheating device for the burner nozzle assembly.
Up to this point, it has been customary to use a cable harness to bring the required connecting lines together and then to attach the individual cables for the respective devices, which were ultimately to be connected to the individual pieces of equipment for the purpose of supplying power to such equipment or operating parts. A cable harness, however, not only occupies a relatively large space in the area of the burner unit, but has also proven to lead to connecting errors during assembly when, for instance, there is a mix-up of the individual cable leads. While a final check of the heating device should reveal such errors, the fact remains that the heating device has to be dismantled and connections have to be reworked. Also, the components involved may be damaged during this time-consuming and complicated process, resulting in a further drawback, since an exchange of defective operating parts is costly.
Accordingly, it is a primary objective of the invention to provide a connection device for a power supply which eliminates the problems outlined above; which connection device has a compact design, is easily assembled and substantially eliminates errors in connecting the equipment. Furthermore, it is a particular objective that the connecting device can be universally used for various types of heating equipment facilitating cost-effective production and inventory.
In accordance with the invention, the connecting device has a central common connecting component which collectively combines the connections and connecting devices for equipment to be connected. This central connecting component can be secured to a flange of a heating device housing part supporting the burner unit.
In the arrangement, in accordance with the invention, there is no requirement for a cable harness in the area of the burner unit, as the central connecting component simultaneously assumes the function of distributing the power supply. The main current supply is connected with its central connecting component, and all additional distribution elements are provided within the connecting component. Since the supply lines of the individual components do not have to be separately attached during assembly and connection of the necessary operating equipment, assembly is considerably simplified. Moreover, errors in connecting the lines to the respective equipment are eliminated, and there is a total saving in installation space, with the result that a compact design of such a heating device is achieved with improved safety.
Preferably, there are plug connectors attached to the connecting component for equipment to be connected, so that such equipment can be directly connected with the common connection component. Via the plug connection the equipment to be connected can also physically be secured to the connection component. If the equipment requires a switching element, like a relay, such relay, in accordance with the invention, is appropriately secured to the connection component, and, preferably, is secured in proximity of the plug connectors for the devices to be associated with the relay. Whether the equipment is connected directly at the connecting component, or is connected by interconnection of a relay, depends upon the operating mode and type of equipment to be connected. For example, connection via a relay is required for a combustion motor or a circulating pump. In order to avoid errors during connection, the relays are arranged in proximity of the plug connectors for the equipment to be connected.
In accordance with a further refinement of the invention, the connecting component is formed as a housing containing the electrical connection to be actuated and the current distributors. Thus, these are contained and protected in the housing eliminating the requirement for long line connections which tend to be wasteful. Hereby, the connection component can be designed as a unitized connection plate or printed circuit board, for instance.
Preferably, the plug connectors and switching devices for the equipment to be connected to the connecting component are provided in close proximity to the equipment to be connected at the component, so that a direct connection via plug contacts can be established. For instance, the following are arranged on the rear side of the connecting component, i.e., the side facing away from the burner unit: the switching device for the combustion motor with its associated plug connection, a plug connection for the control unit and motor with its associated plug connection, a plug connection for the control unit, and the switching device for the circulating pump. Furthermore, at the peripheral surface of the connection component, there may be provided a plug connector which preferably is accessible via an opening in the flange so that, after completion of the heating device assembly, connection to a vehicle or other external power supply can be effected in a simple and expedient manner.
On the front side of the connection component (the side facing the burner unit), there are provided connecting devices for the ignition spark unit, a plug connection for the flame monitoring device, and a plug connection for the solenoid valve. Since these components are directed towards the combustion chamber of the heating device, they are combined on the front side of the connection component. If the heating device also comprises a preheating device for the burner nozzle assembly, a plug connector therefor is also provided on this front side. In order to avoid misalignments and surface mismatches during assembly of the connection component to the flange of the heating device housing part, the outer contour of the connection component is selected such that it will mate against receiving devices for the combustion motor in a positively engaged manner, whereby such receiving devices (which, for instance, may be formed by castings in the flange are) are, however, accessible even after the connection component has been mounted at the flange.
Thus, in the connecting device in accordance with the invention, the operating parts to be connected in the form of plug connectors, are attached at a common central connection component, so that substantially low-loss connections are obtained with a surprisingly simplified assembly. The alignment of the central connection component can always be adapted to the requirements of the respective type of heating device in that, for instance, individually prepared and provided plug connectors are not utilized, and are only utilized when required. Hereby, the common central connected component is universally applicable to heating devices of different heating capacity. Moreover, defective equipment to be replaced can be quickly and easily exchanged at the plug connectors provided.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the preset invention.